Some vending machines have been adapted to dispense coupons or tickets in association with the delivery of products from the machines. The coupons or tickets are stored in the machine in sheet form and, accompanying the delivery of the products, are transported from a storage stack through a slot in the machine face.
Although the coupons or tickets dispensed from the machines have been shown to increase sales from the machines, the dispensers have lacked reliability. The individual sheets can become jammed and block further operation of the dispenser until the vending machine is next serviced.
On-demand printing of coupons has also been added to vending machines to print coupons in electronic storage. Continuous roll paper has been used as a paper supply for on-demand printing. Although less susceptible to jamming, a cutting operation required for separating the individually printed coupons raises other reliability issues. In addition to the printer itself, which requires servicing, the cutter adds another moving component subject to breakdown. Electronic transfer of coupon information adds more complexity so that, overall, the servicing requirements for on-demand printing in vending machines have been excessive.
While controlling multiple vending machines remotely within a common network is technically feasible, the current processing capability of vending machines is limited and network hookups would be difficult in many locations and expensive to maintain. Generally, the vending machine owners are not also the owners of the sites on which the machines are placed.